Carrier 38AH044-134 - Manual (Page 51)

TROUBLESHOOTING
PROBLEM SOLUTION
COMPRESSOR DOES NOT RUN
Contactor Open
1. Power off.
2. Fuses blown in field power circuit.
3. No control power.
4. Thermostat circuit open.
5. Multi-function timer not operating.
6. Compressor circuit breaker tripped.
7. Safety device lockout circuit active.
8. Low-pressure switch open.
9. High-pressure switch open.
10. Discharge gas temperature switch open.
11. Loose electrical connections.
12. Compressor stuck.
Contactor Closed
1. Compressor leads loose.
2. Motor windings open.
3. Single phasing.
1 Restore power.
2 After finding cause and correcting, repiace with correct
size fuse
3. Check secondary fuse(s); replace with correct type and
size. Replace transformer if primary windings receiving
power.
4. Check thermostat setting.
5. Check timer for proper operation; replace if defective.
6 Check for excessive compressor current draw. Reset
breaker; replace if defective
7. Reset lockout circuit at thermostat or circuit breaker.
8 Check for refrigerant undercharge, obstruction of indoor
airflow, or whether compressor suction shutoff valve is
fully open. Make sure liquid line solenoid valve(s) is
open
9. Check for refrigerant overcharge, obstruction of outdoor
airflow, air in system or whether compressor discharge
valve is fully open Be sure outdoor fans are operating
correctly
10 Check for open condition. Allow for reset. Replace if
defective
11. Tighten ail connections
12 See 06E compressor service literature.
1 Check connections.
2 See 06E compressor service iiterature.
3. Check for blown fuse. Check for loose connection at
compressor terminal_____________________________________
COMPRESSOR STOPS ON HIGH-PRESSURE SWITCH
Outdoor Fan On
1. High-pressure switch faulty.
2. Airflow restricted.
3. Air recirculating.
4. Noncondensables in system.
5. Refrigerant overcharge.
6. Line voltage incorrect.
7. Refrigerant system restrictions.
Outdoor Fan Off
1. Fan slips on shaft.
2. Motor not running.
3. Motor bearings stuck.
4. Motor overload open.
5. Motor burned out.
1 Replace switch
2 Remove obstruction.
3. Ciear airflow area.
4. Purge and recharge as required
5. Purge as required.
6 Consult power company
7. Check or replace filter drier, expansion valve, etc. Check
that compressor discharge valve is fully open
1 Tighten fan hub setscrews.
2. Check power and capacitor.
3. Replace bearings
4. Check overload rating Check for fan blade obstruction.
5 Replace motor.__________________________________________
COMPRESSOR CYCLES ON LOW-PRESSURE SWITCH
Indoor-Air Fan Running
1. Filter drier plugged.
2. Expansion valve power head defective.
3. Low refrigerant charge.
Airflow Restricted
1. Coil iced up.
2. Coil dirty.
3. Air filters dirty.
4. Dampers closed.
Indoor-Air Fan Stopped
1. Electrical connections loose.
2. Fan relay defective.
3. Motor overload open.
4. Motor defective.
5. Fan belt broken or slipping.________________________
1. Replace filter drier
2 Replace power head
3. Add charge. Check low-pressure switch setting.
1. Check refrigerant charge
2. Clean coil fins.
3. Clean or replace filters.
4. Check damper operation and position.
1. Tighten all connections
2 Replace relay.
3 Power supply.
4 Replace motor
5. Replace or tighten belt
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